Pictures: Venice Flood Makes a Swimming Pool of St. Mark's

Share this gallery

Comment on this gallery

Pictures: Venice Flood Makes a Swimming Pool of St. Mark's

1 / 11

Off the Deep End?

Floods in Venice usually mean breaking out the waders, but a few adventurous souls in St. Mark's Square threw in the towel Sunday and stripped down to swimsuits.

It's normal for Italy's "eternal city" to flood in winter, but Sunday's 5-foot (1.5-meter) inundation is the sixth highest since record-keeping began in 1872, according to the Reuters news service. (Interactive map: See how much of Venice floods at different water heights.)

"Usually flooding occurs when there is high tides and rain." Recently "strong winds from the south further enhanced the high-tide conditions," explained Shimon Wdowinski, a geophysicist at the University of Miami.

Most parts of Venice don't flood during the acqua alta ("high water"), but on Monday three-quarters of the city was underwater. As of Tuesday, the water level has begun to recede, but it may take a while, Wdowinski said. "Venice sits in a lagoon that has three outlets to the Adriatic Sea. In cases of heavy rain, like now, it takes time for the water to flow out."

Days before Venice floodwaters reached their current record levels, a woman and child play in St. Mark's Square on October 27. While tourists in the lagoon city may be taking the unusually high tides in stride, related flooding has claimed lives outside of Venice. In Tuscany two men and a woman died when their car fell off a collapsed bridge on Tuesday.

Photograph by Luigi Costantini, Associated Press

Early Departure?

A tourist shoulders her suitcase in Venice's St. Mark's Square on Sunday. (Travel tips: Venice must-dos.)

On average, the high tides submerge the lowest 14 percent of Venice four times a year, but this past weekend's flood levels affected 70 percent of the city. During floods, Venice erects several miles of wooden walkways, called passerelle, across the city, and many hotels keep galoshes on hand.

Photograph by Luigi Costantini, Associated Press

Wet Bar

People dressed in rain gear sit on chairs in a flooded St. Mark's Square in Venice earlier this month. (See National Geographic pictures of "vanishing Venice.")

The MOSE project, sometimes called "Project MOSES," could help reduce flood damage. Begun in 2003 and slated for completion in 2014, MOSE will string four giant barriers made of hollow steel floodgates across the three inlets to Venice's lagoons.

When unusually high tides threaten to flood the city, air will be pumped into the gates to make them buoyant. The gates will rise, sandbagging the city against the rising tide. When the tide recedes, water will flow back into the gates, causing them to lower.

Photograph by Manuel Silvestri, Reuters

Rising Tide Lifting All Boats

During this month's floods, a kayak glides over a barrier at the edge of St. Mark's Square that would normally stop the boat cold.

Venetian flooding could someday be buffered by Project MOSES, but the sea gates aren't the only options under review.

Other scientists have suggested injecting billions of gallons of seawater into porous sediments beneath the island city, inflating them and raising Venice by as much as a foot (30 centimeters) over a period of several years.

Proponents of this idea say that it could compliment the MOSE project and reduce the number of times MOSE would have to be used from 35 times a year to 4.

While subsurface fluid injection has been used by oil companies to raise land in California and Canada, the technique has never been tried on a city, Wdowinski said.

"It's a very interesting idea ... but it could cause structural damage to the city," he added. "They'll want to do a test site before trying it on Venice."

Photograph by Manuel Silvestri, Reuters

First Responders

Prior to Venice's record flooding this past weekend, nurses carry a man on a stretcher on November 1.

In the same way Hurricane Sandy, which devastated portions of the U.S. eastern seaboard last month, was strengthened by its merger with another storm, the flooding in Venice this weekend was made worse by the combination of two large weather systems, meteorologists say.

Apparently protected from record floodwaters, a man rests in a Venice shop Sunday. The annual floods are made worse by the fact that the city is currently sinking about 0.08 inch (2 millimeters) per year, according to a study co-authored by Wdowinski that was published in the journal Geochemistry, Geophysics, Geosystems earlier this year.

Photograph by Manuel Silvestri, Reuters

Life on Hold

A woman stands atop a bench to escape rising floodwaters in Venice on Sunday. (Venice quiz: How well do you know the eternal city?)

Not only is Venice sinking at a slow-but-steady rate, but the surrounding Adriatic Sea is swelling, scientists say. The local sea level is predicted to rise by perhaps a foot (30 centimeters) by the end of this century, hydrologist Giuseppe Gambolati told National Geographic News in 2011.

Photograph by Manuel Silvestri, Reuters

No Boots? No Problem.

With plastic bags tied around their legs, tourists strolled through Venice on Sunday.

Scientists predict that Venice will flood more frequently as sea levels rise and storms become more intense due to global warming. Climate change computer models predict that "the pattern of the rain will change," the University of Miami's Wdowinski said. "We'll have more of these strong events."

Even under the worse case climate change scenario, Venice won't become completely drowned anytime soon, scientists say. "That would require a sea level rise of about 30 feet [9 meters], and that won't happen in the next century," Wdowinski said.